Intermediate Wheel - Second Attempt

I`m really pleased. Here is what has changed since my last attempt:

1. Clockmakers CZ120 engravers brass, I would never bother trying with soft brass again!!
2. A new sharp hardened cutter
3. My new CNC rotary table which worked a treat!

I`m really pleased. I`m going to re-do it as I still feel the teeth are a touch spiral which indicated my cutter was not centre. I spent a good 10 minutes eyeballing the centre with a dead centre held in the rotary table and locking the Z-axis to position. I`m certain it was centre so I need to work out what was wrong, perhaps the cutter is not sitting parallel?

The wheel could possibly run OK as it is only a fraction out and barely noticeable but I think I`ll go for a re-make. Just need to figure how to get this bob on centre height.

These pictures are still on the rotary table with the teeth just cut. They have since been dressed and cleaned up. The difference is the flakes that are still on the photos just flick off and rub off with fine paper where as with the soft brass in my last attempt at cutting, the brass flakes left behind were smudged and could not be cleaned.









Chris

Vertex CNC Rotary Table - finished

Well this is it for now - it is almost finishd, infact I`ve got a bit further than the pictures go because I have now stuck the keypad on the front and made a cheap bezel to hide the screws and frame the display. Still needs a few finishing touches but they are for asthetics, it is fully working now and in position.

The keypad is a standard 4 x 4 matrix which comes with standard number inserts. It took ages getting the alignment right in MS Word and I`m sure there were far far better ways but I eventually got somewhere close and that I am happy with:


And then the box - Maplins Electronics Housing, was a pain to cut, it wanted to split. You can see the two connectors at the bottom, left is a 2.1mm power jack to connect to my old spare laptop charger (which powers both the driver and the indexer) and on the right is a 4 pin DIN connector which I`m using to couple the stepper motor to the box. Since the indexer has 5 profiles for different devices I wanted to be able to change the motor quickly and easily.


This is posed, but I wanted to see what it will look like mounted on the wall next to the mill and well it will look something like this (since the picture was taken, it has now been fitted on the wall). I have printed a mount or bezel that fits around the display, covers the screws and neatens the edge.


I`m really pleased I`ve gone down this route and it has worked really well!

Chris

CNC Vertex Rotary table - part 3 - nearly finished.

I picked up the electronics tonight and will post more details about the source shortly. The electronics to make the indexing divice came to short of £30. I already had a Nema23 stepper motor and Routout Driver 2.5A which were also used. The Driver is shown below:


This is the indexer:


Apparently the electronics is quite straight forward since the "brains" in programmed in the chip. If I`m being honest, it means nothing to me...





However, its functionallity does and it is TRUELY EXCELLENT!!
These are the functions:



I will discuss the rest in time as and when I have played with it more and taken pictures but basically you can step by 0.01 of a degree, 0.1, 1.0 and 10 deg with quick single steps. You can jog in any steps. You can divide 360 in to 0-999 divisions. Continually rotate the table in either direction and even programme in command steps! It is brilliant! Backlash compensation is also included!

To divide which I need for my clock building, you select it from the start menu and enter the number of divisions:


You then press the direction button to move directly to the next division!! No fuss, just a button!!



I just need to encase the hole lot and make some labels for the buttons (which I now know off by heart after using it for the past couple of hours without any markings)!

Rotary Table CNC - part 2 - Complete Motor Mount

Following on from my last post, I drilled and tapped the larger circular motor bracket disk to accept the M5 bolts that would ultimately hold on the motor. I then bored a hole in the centre:





The Oldham couplings arrived - 12mm one side to lock onto the Rotab shaft and 1/4" on the other side for the motor shaft. The the spacer/link in the centre.



All the parts ready to fit together:





And then the motor mount complete:



I have hooked it up to Mach3 and my driver and it is working. I just need to sort out the electronics for division steps.... more to come with a video.

Chris

Rotary Table CNC Conversion

I purchased a Vertex Rotary table (rotab/RT) a few months ago and it has seen some good use but I will hopefully use it even more for dividing in cutting my clock wheels. I have purchased the dividing set as an add-on to the rotary table which comes with three plates for easy dividing. I have studied how to use the dividing plates and after a trial with them, there is no way I can keep concentration for long enough to use them on a 60 - 120 tooth wheel! If it was 1 to 1 then maybe, but I know I`ll mess up eventually and then there are counts which can`t be done with the plates.

I know, I know .... I should be able to use them and people have used them for years and years in the past but I fancy dabbling again in CNC. When I say again, I mean after my horrific failure at converting my X3 mill to a CNC X axis! A failure maybe, but at least I know now the basics of CNC, the software and the basic setup. So here goes, this is Part 1 but I hope the complete setup to be finished within a week of this post:

This is what I am aiming for -



these are £380 for the CNC kit only (i.e not including the table), I`m hoping to build similar with some help on the electronics but more on that in the next post when it has arrived. For now, I just need to remove the handle and make a bracket to fit the motor spindle to the rotab spindle. Basically, it should look like the one above but without the electronics gizmo... for now!

Here goes:

Vertex 4" Rotab with handle removed:



I`m going to need to couple the shafts together and for that I`m buying a 12mm (shaft axis diamter of rotab) to a 1/4" (shaft dia of motor) oldham coupling. This will also compensate small amounts of miss alignment. So basically we just need to bridge the gap and make a support for the motor. I`m using a tube of ally that was in the scrap bin:


It was bored out to leave a little lip on the inside of the bottom end:


A disk was cut and bored with three holes drilled matching the rotary table threaded holes:


The disk drops down the tube and against the lip, when bolted against the rotab is locks the tube onto the table:


When mounted:


Now the motor needs to be mounted on its 4 holes in the position below but I`ll have to space it out another 25mm to fit the oldham couplings that will be inside.



So that is the idea but I need another spacer (ideally a longer tube would have done!) but I also need more width for the motor mounting points. I`m going to use this and once bored out it should work a treat!



Just need the oldham couplings to arrive and then pickup the electronics. More details next episode!

Chris

Clock Parts Wooden Box

A slight aside from the actual clock build, after seeing Jere's watch box for all his parts as he makes them I couldn`t help but want one. Certainly not to Jere's high standards but should serve me well in my dirty workshop! I have made a compartment at the front large enough for the frame and the first row is sufficient size for the larger wheels. I`ve been planning this all weekend and it hasn`t taken me too long to finish...







Last picture is with it up to date and it is a bit empty, perhaps I should now get on with the difficult part of building a clock! .... nope, not yet, a few more clock related jobs and tools to make! Keep posted....

Chris

Ideas for a Pillar Jig

Here is my idea for a pillar jig so that each pillar is identical size.

Making the Pillars

I`ve had a break from filing the frame and decided to do the pillars. I enjoyed this little bit of turning!











The bottom two need drilling and tapping in the centre section for the feet but I`ll do that later when I have finished the feet. The ends are tapped M3 and now I need to complete the washers.

Chris

Cutting the Frames

We cut the frame on my brother-in-laws bandsaw. He did the job while I inspected, irritatingly, over his shoulder.







The frames now need filing together for a good finish. I spent one hour on one long straight last night so I`m guessing this could be a good few hours more work...

The Frames - part 2

After bolting the plates together yesterday I wanted to fit the locating pins so that the plates can be separated and realigned quickly and accurately. I was worried about doing this as the proceedure involved driving a taper pin through from the front face of the front plate and then polishing it out totally so that the plate/pin joint was invisible. I drilled a 1mm hole in three locations for the three pins:



My clockmakers broaches came today so I used this immediately tonight to cut a taper hole right through the front plate. A stub of 1mm was left on the top plate and using a stake the pin was hammered home. The pin was cut on the back plate to leave a 1mm stub. These are the pins in place:



The pins were hammered home from the front face so this now needed filing and then fine sanding to get a perfect finish so the pin was invisible. Hopefully this picture explains what I mean:


Perhaps I am getting over excited but I can`t believe that you can`t see a joint from the front plate yet I am left with three nice little stubs on the back side of the plate which locate perfectly with the back plate.

I then took the hole lot around to my brother-in-laws to cut the plates out with his band saw. This took about an hour to get them roughed out. I now need to file them and after an hour at this tonight, I have a feeling a good few hours are left on this job!! The clock in the picture is also the one I am attempting. Note that I have left in the bolts on little tabs which I`ll cut off when I have finished filing. To be honest, they are overkill and the locating pins with a small clamp would surfice but I`ll leave them for now and then cut the tabs off when I am nearer to finishing.

Thanks for looking...

Chris

The frames - part 1

I`m having a break from wheel cutting for a few days and I`m going to put some time into the frame. I am roughly following the order that Colin says to put it together in, in his book "Clockmaking for the Model Engineer".

The frame will need to be cut out of 5mm engravers brass and both front and back need to be identical. Pivot holes in the frame will need to be drilled together when the time comes so it is essential that the plates can be aligned quickly and accurately when needed for drilling. This is done by using brass taper pins shown in the picture. A pin is driven into the front frame at the top and bottom, the front is then polished off so the pin is invisible from the front view and a small "stub" left on the back side. This stub corresponds to a hole on the back plate allowing easy and accurate aligning. The picture shows the universal taper pins and the brass plates. These thick plates where the most expensive part of the clock:



The plans I recieved are perfectly to scale so I did a photocopy, cut out a template and stuck it to one of the plates whilest clamping them together. I have seen this method used before and it is perfectly acceptable for the plates. The pallet is also roughed out in a similar way when the time comes. The plates were bolted together with M4 screws countersunk at the back side. I will then be roughing this out tomorrow on my brother-in-laws saw but I will be leaving on the little bolt tabs. I`ll cut these off right at the very end, clamp the plates together with the locating pins and finish the plates fully.



And that is where I am at right now. I`ll hammer home the taper pins next and then rough the shape out ....

Thanks for looking.

Wheel Cutter - profile and clearance

I have been fielding a few questions regarding wheather the cutter has sufficient clearance on the front leading edge. This diagram should help clarify the profile of the cutter:



Chris

0.8 mod Wheel Cutter - 2nd Attempt

OK, well I`ve set off on the next attempt at the cutter. I have decided a few things since my last attempt.

1. Use the correct material, a suitable carbon steel and ideally heat treat a piece to test it.
2. I need to be more accurate. I did some more calculations and the difference between module cutters is tiny, clearly I need more precision.
3. I need to really sharpen the cutter.

So with that in mind I decided to dig out my mitutoyo calipers and guage vernier that was given to me from a friend at work a few weeks ago. I haven`t used them yet and I think now is the time to learn. It puts me off because they are imperial but I`m getting much better now switching between metric and imperial over the last few months of reading both.



For the material I ordered some guage plate or ground flat stock as John Shadle suggests in his plans. Whats more, it acutally was advertised as "suitable for hardening for tooling".



I next cut the out a rough disk with the hacksaw. Drilled a hole in the centre and mounted it on the actual arbour that it will be situated on when the cutter is finished. I then trued it up in the lathe and immediately hit problems. This stuff is pretty hard! I remembered a conversation we had on here a few days ago with John (Bogs) and remembered about honing in with a stone on the cutting tip. What a difference it made, the steel started curling and shaving off. I then continued cutting in from both sides, skimming slithers off until eventually I got to a width of .05" for the tooth tip or what will become the gap between teeth. I then took this down to the correct depth for the dedendum of the teeth.



Next I needed to put on the radius 2.5mm. I really wanted to find a more accurate way of doing this but couldn`t think of anything better than John Shadle suggests in the plans. A well if it is good enough there it is good enough for me. I rounded an old 2.5mm drill bit to profile and mounted this in a little holder I made and held it with a grub screw:



I mounted this in the tool post and run the lathe on very slow with lots of oil. I thought I`d hit problems but to my astonishment, the steel started peeling off! I continued until I got to depth for the addendum and removed it all from the chuck:



If you look at the top of the picture below you can see the nice radius profile on the cutter. It looks much better than my previous attempts - much better




.... and then the battery went on the camera!

I`ve not done too much more other than remove it from the arbour and litterally cut the disk in half with a hack saw. I have then taken my time and really sharpened and honed in on the cutter edge. It is now really sharp and shiney. The great thing about this method is that you actually end up with two cutters (each half of the disk) and if an offset hole is drilled on both sides of the half disks, you end up with two cutting sides on both halfs of the cutter. John Shadle says this method takes an hour and I`ve probably put a good two hours already but I`m nearly there. I really hope this works otherwise I`m going to be pestering Stew to get this tool post grinder wheel cutting idea up and running :whip: lol.

I`ll take more pictures tomorrow, hopefully of a finished cutter.

Chris